Conventionally, a substrate processing apparatus has been kwon, in which a substrate, such as a semiconductor wafer or a glass substrate, is processed by supplying a processing liquid.
In such a substrate processing apparatus, a processing liquid may be attached to a nozzle itself after the processing liquid is ejected therefrom, and the processing liquid may remain in the nozzle as a contaminant. When a substrate processing is performed in such a state where the nozzle becomes contaminated, the contaminant attached to the nozzle may be scattered, and thus, the substrate may be fouled. Therefore, the substrate processing apparatus may be provided with a nozzle cleaning device in some cases.
For example, Japanese Patent Laid-Open No. 2007-258462 discloses a nozzle cleaning device that removes contaminants attached to a nozzle by spraying a cleaning liquid onto the nozzle.